Liquid-tight carton and liner



March 1, 1960 M- s. KENNEDY ETAL 2,926,830

LIQUID-TIGHT CARTON AND LINER Filed Feb. 4, 1958 W 5 5 I R Y Q 5 4 wk o 2 VJ /J N M r A N I t H a C xi. A

h IIIIU -45 F O; M

LIQUID-TIGHT CARTON AND LINER Mildred S. Kennedy, Summit, N.J., and Everett V. Loman, Elmont, N.Y., assignors to Electronic Wave Products, Inc., New York,N.Y., a"corporation of New York Application February 4, 1958, serial No. 713,1 6 7 s Claims. crew-=14 This invention relates to a liquid-tight plastic liner and carton assembly.

An object of the invention is to provide an improved cardboard box and liner construction which is able to withstand severevibration and impact and yet remain liquid-tight.

Another object-isto provide a simple and inexpensive way to fabricate a separate plastic liner for use inside a cardboard box.

These and other objects willin part be understood from and in part pointed out in the description given hereinafter.

In transporting certain kinds of liquids, such as softdrinksyrup, battery electrolyte and so forth, it' is highly desirable to use individual containers which can be shipped from the factoryfilled and so delivered to the ultimate consumer, and then thrown away when empty. However, for the use of such containers to be economical they of course must have a low cost. They must also a be strong enough, yet lightweight enough to be shipped without special handling. Otherwise even though a container has a low enough initial cost, the cost of shipping and handling becomes excessive.

One type of recently developed container which is being used more and more to replace glass bottles in many difficult applications is a steel drum having fitted within it a separate liquid-tight liner of a suitable plastic film, such as polyethylene. The advantages of such a container are that, for a given capacity, it weights appreciably less than a glass bottle and it is less vunerable to damage from sudden blows or dropping. Additionally, the initial costof such a container is competitive with bottles and, dependingon the type of plastic used for the liner, it can be used to carry very corrosive liquids or conversely those whichmust be kept absolutely free of contamination The ,success .-of the lineddrum-t-ype .ofcontainer has created a growing demand for even better, less expensive containers. The goal sought is to be able to pack and ship all types of liquids in cardboard boxes in much the same way that great varieties of non-liquid goods are now handled. Cardboard boxes are commercially available in almost any size at very low cost and their weight to strength ratio is excellent. Also, because of the ease of working with paper rather than metal, paper boxes are often greatly preferred by the consumer. Furthermore, because of the mechanical and thermal insulation qualities of paper, corrugated boxes protect their contents against certain abuses, such as dropping or extremes of temperature better than a metal drum can.

In the past various arrangements for making a cardboard box liquid-tight have been tried. None, however, so far as is known has proved entirely satisfactory. One such arrangement consisted in simply coating the inner surface of the box with a liquid-impervious material. In the case of a wax coating, though this was relatively easy and inexpensive to apply, the sealed box 2,926,830 Patented Mar. 1, 1960 was extremely vunerable to sudden blows. which caused the wax lining to crack and the box to leak. Another arrangement used an adherent plastic film instead of wax but with this it was very difficult to fabricate the' box blank and then to completely seal it. This made the.

cost too high. h

To avoid these difficulties with linings integral with the box walls, liners of thin plastic film have been fabricated separate from the boxes and then placed inside them. However, new difficulties arose. Now, because the liners were separate from the box walls, the

two rubbed together and eventually wore through the thin soft liner. Sometimes, instead, the liner walls would flex in and out with the sloshing of the liquid back and forth inside and this quickly fatigued the; liner and caused it to rupture. The present invention effectively overcomes these ditnculties. 1

In accordance with the present invention there is pro-i.

vided a one piece liquid-tight liner having a cubical or rectangular shape. Formed integral with the liner are tabs or flaps by which it can be attached inside a cardboard box. it is fitted inside a box result in a container able to retain liquid without leaking even through subjected to strenuous vibration and sudden shocks, such as dropping.

This container thus constitutes a nearly ideal liquid Figure 2 is a plan view in reduced size of the blank 1 from which the inner cover of. the box is formed;

Figure 3 is a perspective view from above of the liner itself;

Figure 4 is a perspective view in reduced scale showing the pattern of the liner and Figure 5 is an enlarged fragmentary cross-section view of the corner of a completed box with liner.

The box shown in Figure 1 comprises an outer cardboard cover 12 of standard construction and an inner cardboard cover 14 made in one piece and then folded into cubical form with an open bottom. A separate piece prior to folding and sealing;

of cardboard (not shown) can be used to cover this open bottom. Inner cover 14, which is folded from a. fiat;onepiece blank seen in reducedsize in-Figure'2,

includes six side panels 16, 17, 18, 19, 20 and 21, panel 16 though shown broken away being the same size as the others. Panels 17 and 19 are joined to panel 18 along vertical edges of the cover and in like manner panels 16 and 20 are joined to panel 21. Panels 18 and 21 are joined along their top edges to opposite sides, respectively, of the top panel 24 to which also are connected along the remaining pair of sides the flaps 26 and 28. When inner cover 14 is folded to its final position, flap 26 folds down upon panel 16 which in turn is folded over upon panel 17. Similarly, flap 28 is against panel 20 which in turn is folded over panel 19.

During assembly, a liquid-tight liner 30 is placed inside inner cover 14 and secured to it so that when the completed container is filled with liquid, the liner will be protected from damage due to excessive flexing and abrasion. Figure 3 shows the liner by itself, the liner being made from a single short length of thin plastic tubing 32, seen in reduced size in Figure 4, which is then folded The structure of this liner and the way-- shown in Figure 3 it can be sealed along the opposite top edges 34 and 36 and transversely across the top at seam 37. An excess of material is left adjacent edges 34 and 36 to form the narrow, double layer flaps 38 and 40', respectively, the corners of these flaps being tapered inward as shown. In a similar Way, but without edge flaps, the bottom of liner 30 as seen in Figure 1 is sealed along the opposite bottom edges 42 and 44 and across seam 46. The sealing of the layers of tubing 32 is accomplished by heating and pressing or preferably by dielectric welding. The top of liner 30 is provided with a welded-on closure 50 through which it can be filled and emptied. This closure as seen in Figure 4 is positioned and clamped by the metal flange 51 in the center of opening 52 through the top of the box. 7

- As seen in Figure 1, the flaps 3'8 and 40 along top edges 34 and 36 of theliner are attached to respective ones of flaps 26 and 28 ofinner cover 14 by two or more of the staples 54. Then, the cover flaps are folded down and this sub-assembly is placed inside outer cover 12 which is finally sealed. In the finally assembled carton, the liner flaps are folded down over the tops of panels 16 and' 17 and panels 19 and 20 respectively and are supported along their length by the top edges of these flaps.

'Flaps 38 and 40 are the only portions of the liner, except for the top closure, adhering or fastened to the box. Thus a certain amount of freedom for the liner to conform to the box as it is being stressed or strained is permitted but destructive flexing or rubbing is prevented. The inner faces of inner cover 14 are advantageously waxcoated to give low friction.

The relationship of a liner fiap and the panels of the 0 box when sealed is given in Figure 5 which shows the flap 40, the opposite liner flap being positioned in a corresponding-way. It will be seen that liner flap extends over the top edges of box panels 19 and 20 and then down alongside cover flap 28 to which it is fastened by staples 54. Thus, one top edge 36 as well'as the opposite top edge 34 of the liner are supported along their length and held parallel with some degree of firmness. Accordingly, when the box is filled with liquid, destructive flexing or rubbing of the liner inside the box is prevented.

In an actual container built according to the invention, the shape of the liner and box was substantially the same as shown in the drawings and thedimensions of the liner were approximately 9 /2 inches square by 13 /2 incheshigh. Flaps 38 and 40 were each about 1 inch wide. The liner was made of 12 mil (0.012 inch) polyethylene dielectrically sealed and it had a capacity of 5 gallons. The inner and outer covers were corrugated paper board. This container, filled with water, was not damaged by a four foot drop onto a hard floor and the container thereafter survived a standard vibration test.

The above description of the invention is intended in illustration and not in limitation thereof. Various changes may occur to those skilled in the art and these may be a plurality of fasteners pinning said flaps to the inner faces of said fold-down cover flaps, said liner flaps being folded down over the top edges of respective side panels,

and a top closure sealed to said liner and centered within an opening in said covers.

. 2. An improved liquid-tight carton comprising: an' outer box cover, an inner cover having a top panel, two

fold-down flaps and six side panels folded into box shape, a one-piece liner of relatively thick gauge polyethylenelike film folded into box shape and sealed along two opposite top edges and a bisecting top seam, and along two opposite bottom edges and a bisecting bottom seam, said liner having narrow flaps along said sealed top edges, a plurality of fasteners pinning said flaps to the inner faces of said fold-down cover flaps, said liner flaps being folded down over the top edges of respective side panels, and a top closure sealed to said liner and centered within an opening in said covers.

3. In a liquid tight carton comprising an outer box cover, an' inner cover having a top panel, two fold-down flaps and six side panels folded into box shape, an improved one-piece liner of relatively heavy heat-scalable plastic film, said liner comprising a short length tube folded into generally cubical shape and heat sealed along two opposite top edges and a top seam bisecting said edges and heat sealed along two opposite bottom edges and along a bottom seam bisecting said bottom edges, said liner having narrow flaps along said sealed top edges which are adapted to be fastened to the inner faces of said fold-down cover flaps to prevent destructive flexing and abrasion of said liner inside said inner cover, said liner having a top closure sealed to it and adapted to extend through an opening in said outer and inner covers.

References Cited in the file of this patent UNITED STATES PATENTS 2,370,680 Moore Mar. 6, 1945 2,375,809 Moore May 15, 1945 2,382,536 Baxter Aug. 14, 1945 2,493,337 Buttery Jan. 3, 1950 2,689,077 Main Sept. 14, 1954 2,801,782 Ingham Aug. 6,1957 

